Improving the appearance of the skin has been the goal of many esthetic products and procedures for many years, since a tight skin, without wrinkles or cellulite, has a younger and more appealing appearance. Apart from age related changes, the skin also suffers from exposure to chemical and physical injuries, such as tobacco, cosmetics, esthetics and radiation from the sun and other sources. Those factors contribute to the decrease in collagen production, to reduced elasticity, and the appearance of wrinkles.
The skin and muscles of the face are structured differently than other places on the body. One side of the facial muscles is connected to the bone and the other to the skin. As the muscle deteriorates through the aging process, the attached facial skin loses it elasticity. Loss of elasticity causes the skin to sag and wrinkle. Strengthening relevant muscle groups restores and maintains the original shape and contour of the muscles. As facial muscles get stronger, they get shorter and flatter, causing the attached skin to become firmer, and smoothing wrinkles, improving facial appearance. Additionally, a contracting muscle's blood supply is 10 times greater than a muscle at rest. This fresh blood supply delivers vital oxygen and nutrients to the skin, revitalizing the tissue.
The most common method of heating the dermis, is the use of RF radiation, applied by antenna or electrodes. For example, WO98005380 discloses a method of tightening skin using an RF electromagnetic energy delivery device. However, the manner (and specifically, the protocol) in which the RF is transmitted to the region of interest is highly important. Some methods will have no effect and others may have the opposite effect.
U.S. Pat. Appl. 20100016850 discloses an invention that demonstrates that application of electrical currents of about 1 milliampere, and voltages greater than 4V have a much greater esthetic effect on the skin than application of lower currents and voltages known in the prior art. This application further discloses that simultaneous application of electrical currents on the skin yields better esthetic results.
All of the RF devices known in the prior art irradiate the tissue with RF energy that has a single phase. This means of irradiation is relatively inefficient, because the waveform necessarily passes through zero twice per cycle; that is, there will inevitably be periods of irradiation during which no energy is being transferred to the skin.
Thus, means for providing RF (or in general, any kind of energy) to the region of treatment (e.g., the skin) in which an essentially continuous transfer of the energy (e.g., the RF) to the skin remains a long-felt, yet unmet, need.